1. Field of the Invention
The present invention relates generally to transport belts (sometimes referred to in the art as conveyor belts), particularly to a method and apparatus for cleaning a transport belt and, more specifically, to cleaning a print media transport belt in an ink-jet hard copy apparatus.
2. Description of Related Art
The art of ink-jet technology is relatively well developed. Commercial products such as computer printers, graphics plotters, copiers, and facsimile machines employ ink-jet technology for producing hard copy. The basics of this technology are disclosed, for example, in various articles in the Hewlett-Packard Journal, Vol. 36, No. 5 (May 1985), Vol. 39, No. 4 (August 1988), Vol. 39, No. 5 (October 1988), Vol. 43, No. 4 (August 1992), Vol. 43, No. 6 (December 1992) and Vol. 45, No. 1 (February 1994) editions. Ink-jet devices are also described by W. J. Lloyd and H. T. Taub in Output Hardcopy [sic] Devices, chapter 13 (Ed. R. C. Durbeck and S. Sherr, Academic Press, San Diego, 1988).
FIG. 1 (PRIOR ART) depicts a hard copy apparatus, in this exemplary embodiment a computer peripheral, ink-jet printer, 101. A housing 103 encloses the electrical and mechanical operating mechanisms of the printer 101. Operation is administrated by an electronic controller 102 (usually a microprocessor or application specific integrated circuit (xe2x80x9cASICxe2x80x9d) controlled printed circuit board) connected by appropriate cabling to a computer (not shown). It is well known to program and execute imaging, printing, print media handling, control functions and logic with firmware or software instructions for conventional or general purpose microprocessors or with ASIC""s. Cut-sheet print media 105, loaded by the end-user onto an input tray 120, is fed by a suitable paper-path transport mechanism (not shown) to an internal printing station where graphical images or alphanumeric text is created. A carriage 109, mounted on a slider 111, scans the print medium. An encoder subsystem 113 is provided for keeping track of the position of the carriage 109 at any given time. A set of individual ink-jet pens, or print cartridges, 115xe2x80x9cXxe2x80x9d is mounted in the carriage 109 (generally, in a full color system, inks for the subtractive primary colors, cyan, yellow, magenta (X=C, Y, or M) and true black (X=K) are provided; in some implementations an ink-fixer chemical (X=F) is also used). An associated set of replaceable or refillable ink reservoirs 117xe2x80x9cxxe2x80x9d is coupled to the pen set by ink conduits 119. Ink is deposited on the sheet of media 105 at a xe2x80x9cprint zone,xe2x80x9d or xe2x80x9cprinting station,xe2x80x9d 107. Once a printed page is completed, the print medium is ejected onto an output tray 121. The carriage scanning axis is conventionally designated the x-axis, the print media transit axis is designated the y-axis, and the printhead firing direction is designated the z-axis.
For convenience of describing the ink-jet technology and the present invention, all types of print media are referred to simply as xe2x80x9cpaper,xe2x80x9d all compositions of colorants are referred to simply as xe2x80x9cink,xe2x80x9d and all types of hard copy apparatus are referred to simply as a xe2x80x9cprinter.xe2x80x9d No limitation on the scope of invention is intended nor should any be implied.
FIG. 2 is a schematic depiction of another ink-jet hard copy apparatus 210 as may be associated with the present invention. A writing instrument 115X is provided with a printhead 214 having drop generators including nozzles for ejecting ink droplets onto an adjacently positioned print medium, e.g., a sheet of paper 105, in the apparatus"" printing zone 107. A perforated, endless-loop belt 232 is one type of known manner printing zone input-output paper transport. A motor 233 having a drive shaft 230 is used to drive a gear train 235 coupled to a belt pulley, or roller, 238 mounted on a fixed axle 239. A biased idler wheel 240 provides appropriate tensioning of the belt 232. The belt rides over a platen 236 (sometimes including heating devices) in the print zone 107 associated with a known manner vacuum induction system 237. The paper sheet .105 is picked from an input supply (not shown) and its leading edge 254 is delivered to a guide 250, 252 where a pinch wheel 242 in contact with the belt 232 takes over and acts to transport the paper sheet 105 through the printing zone 107 (the paper path is represented by arrow 231). Downstream of the printing zone 107, an output roller 244 in contact with the belt 232 receives the leading edge 254 of the sheet 105 and continues the paper transport until the trailing edge 255 of the now printed page is released.
Ink-jet technology is used to describe the present invention even though it has wider applicability because the ink-jet environment typifies a transport belt use where the local environment may contain contaminants such as ink mist and paper dust which can soil a transport belt and clog perforations in a vacuum belt or even be sucked through the belt, contaminating the subjacent platen and other subsystems of the apparatus. Furthermore, the latest generation of ink-jet printers has found commercial success for economical color printing of high resolution graphics, including photographic reproductions, which require edge-to-edge paper printing (referred to as xe2x80x9cfull bleedxe2x80x9d). Overspray and aerosol will build up on the belt over time. Not only does this affect performance of the belt itself, ink on the belt can be transferred undesirably to the back side of the print, particularly if the ink remains in a liquid or semi-fluidic state.
It can also be recognized that this type of problem can occur in other vacuum transport systems such as for transporting thin sheets of metal where particulate flakes might be present or for coating processes where an aerosol spray is used on a passing receptor on the transport belt.
Thus, there is a need for a method and apparatus for cleaning transport belts.
A method and apparatus for cleaning a perforated, transport belt has belt surface cleaner mechanisms that include a pair of moveable, consumable webs. A scrubbing of the belt by a wet web is followed by a scrubbing of the belt by a dry, absorbent web. A solvent dispensing mechanism can be fluidically coupled to re-soak the wet web. Mechanisms for selectively engaging and disengaging the belt surface cleaner mechanisms ensure free belt travel during flexible material transport and the cleaning of both surfaces during cleaning cycles. The system includes consumable piece-part elements for refurbishing and remanufacturing.
In a basic aspect, the present invention provides a method for cleaning a transport belt, including the steps of: positioning a solvent-bearing cleaning web in non-contacting juxtaposition to a transport surface of the belt; positioning a dry cleaning web downstream of the cleaning web in non-contacting juxtaposition to the transport surface of the belt; and selectively repositioning both the solvent-bearing cleaning web and the dry cleaning web into contact with the surface.
In another basic aspect, the present invention provides a transport belt cleaning apparatus including: first web means for wet cleaning mounted adjacently an outer surface of the belt; mounted downstream of the first web means, second web means for dry cleaning the outer surface; means for selectively engaging the first and second web means with the outer surface.
In another basic aspect, the present invention provides an ink-jet hard copy apparatus including: a transport belt for media input-output; a belt inner-surface cleaner; and a belt outer-surface cleaner, including a first movable wet web and a second movable dry web mounted downstream of the wet web, wherein the inner-surface cleaner and outer-surface cleaner are releasably engagable with the belt.
In another basic aspect, the present invention provides a method for re-furbishing an ink-jet printer having a vacuum belt cleaning apparatus including the steps of: removing the cleaning apparatus; and replacing the cleaning apparatus.
In another basic aspect, the present invention provides a consumable ink-jet vacuum belt cleaning apparatus including: mounts for positioning cleaners in contraposition to each side of the belt; and cleaners affixed to the mounts.
In another basic aspect, the present invention provides an ink-jet hard copy apparatus endless-loop, vacuum-actuated, media transport belt cleaning system including: a renewable first belt cleaning subsystem mounted adjacent an inner surface of the belt, including at least one belt wiper; and a renewable second belt cleaning subsystem mounted adjacent an outer surface of the belt, including a first web, bearing a belt cleaning solvent and, downstream of the one web, a second web fabricated of material for absorbing the cleaning solvent, wherein the first belt cleaning subsystem and second belt cleaning subsystem are contraposed with the belt therebetween and are selectively engagable and disengagable with the respective inner surface and outer surface.
Some advantages of the present invention are:
it provides a self-contained subsystem which may be repaired, replenished, or replaced independently the transport belt subsystem;
it provides commercial implementation using consumable parts which can be obtained and installed by the end user; and
it provides a simple re-manufacture capability to the apparatus in which it is implemented.
The foregoing summary and list of advantages is not intended by the inventors to be an inclusive list of all the aspects, objects, advantages and features of the present invention nor should any limitation on the scope of the invention be implied therefrom.
This Summary is provided in accordance with the mandate of 37 C.F.R. 1.73 and M.P.E.P. 608.01(d) merely to apprise the public, and more especially those interested in the particular art to which the invention relates, of the nature of the invention in order to be of assistance in aiding ready understanding of the patent in future searches. Other objects, features and advantages of the present invention will become apparent upon consideration of the following explanation and the accompanying drawings, in which like reference designations represent like features throughout the drawings.